1. Field of the Invention
The present invention relates to a forgery-preventing film which is highly effective for protection against forgery and is usable in bank notes, bills, checks, traveler's checks, securities, cards and others that must be protected against forgery and falsification.
2. Description of the Background
In modern society, numerous documents and cards with forgery and duplication being prohibited are in circulation, such as bank notes, checks, securities, and cards. The forgery and duplication of these items must not only be prohibited by law, but must also be rendered technically impossible to maintain social order. However, copying and duplication technologies have made alarming strides in recent years, with the risk of forgery and duplication increasing each year. The crime of forgery has been increasing of late, and the techniques employed are becoming ever more sophisticated.
For various cards heretofore in use, information-concealed cards are known as in FIG. 2, in which some information common to the card-issuing company such as the company's name, trademark or the like is printed (25) on at least one surface of a card substrate (21) of, for example, white polyvinyl chloride resin or polyester resin through offset printing, gravure printing, silk screen printing or the like, and a laminate film (22) of transparent resin for protection of the common information is laminated on its surface, and an information print part (23) with a piece of information to be concealed and an information-concealing layer (24) for concealment of the information print part are formed in order on that surface to thereby conceal the letter information printed in the information print part. Cutting off the information-concealing layer from the cards of the type makes it possible to recognize the letter information printed in the information print part.
However, the information-concealed cards having the constitution as above are problematic in that light transmittance therethrough from the back face thereof may make it possible to recognize the letter information to be protected in them even though the information-concealing layer is not removed.
The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a forgery-preventing film through which information could not be readily read out.